Gun perforator and method



April 18., 1939. l. J. MccuLLouGH GUN PERFORATOR AND METHOD Filed May19, 1936 2 sheets-sheet 2 Z'NVENTOR IRA J 75V Mc Cu/ L ouGH ATTORNEY.

Patented Apr. 1 8, 1939y or-'ic GUN rnnrona'ron AND Ms'rnon Ira J.McCullough, Los Angeles, Calif. Application May 19, 1936, serial No.80,548 2s claims. (er 16s-0.5)

My invention relates to the art of perforating well casing, and relatesparticularly to a well casing perforating gun for use in perforatingcasing which has already been installed in the well.

5 In o rder that the features and advantages of my invention, as well asthe objects thereof, may

be readily understood, brief reference will be made to the oil producingindustry in which my invention has broad application.- i l0 It is commonpractice .to install in an oil well a wellcasing or oil string and toprovide theportion of this well casing adjacent the oil bearing sandswith perforations which allow oil to flow from the oil bearing sandsinto the well. There I l! are two methods ofperforating the casing. One

is to perforate the. casing before itis installed in the well. The othermethod is to perforate lthe casingat desiredelvations after it has beeninstalled in the well. The method of perforating the casing after it hasbeen ,installed Vin the well may be used either on new wellswhich havenot owed oil or may be used on old wells where it is desired to placeadditional perforations in the casing or perforations at differentelevations so.-

that oil sands which have not been previously utilized may be used. i

It is an object of my invention to provide a de- '.vicefor perforatingcasing after it has been inv stalled in a well in which projectiles orperforat ing elements are shot through thecasing and into the formation.

It is another object of my invention to provide a perforator of thecharacter mentioned in the preceding paragraph in which a pluralityofpro- Jectiles or perforating means isv simultaneously c shot through thecasing and into the oil sands in order that a heavy vibration will beset up which will cause vibration of the well casing, as well as thesurrounding oil bearing formation, in order to disturb the oil bearingformation and create or form channels through which oil may ow to the acasing so thatL it may thereafter ilow through the perforations thusvformed in the casing and into the well.

Lis It is a further object of my invention to proa method and deviceofthe character mentioned in the preceding paragraph in which all of thering charges, that is,-the^charges of powder which propel the differentprojectiles, are substantially simultaneously nghted by means 'of an '5ignition flame which isformed within the perforating device. 5

It is a further object of. my invention to provide a method of firing agun perforator in which an ignition charge in a confined space isignited to 10 produce heated gases and build up pressure so as to ignitea firing charge in another oo nned space through a restrictedpassageway.

It is a further object of my invention to provide a fool-proof and safemechanical actuating means l5 whereby the powder may be ignited at ythedesired time. t L v y It is a further object f my invention, to providean operating means in which the 'percussioni means or the'means whichinitiatesgtheoperation 120 of the apparatus is operated by means ofahamv mer which is dropped into the well'from the'surface of the ground,preferably. around/the cable, by means vof which the perforating deviceislowered into the well. f 1

Itis another objectofmy invention to provide a well perforating deviceof the character mentioned in which the percussion means has'a dis-f fconnectable means so that the percussionmeans is inoperative except whenthe-disconnctable 30 means is in a certain position;V is a safeguardagainst accidental or inadvertentoperation. It is a still further objectofmy invention to provide a perforating device ofthe character re.

ferred to heretofore in `which the percussion 35 means has a retainingmeans associated lwith it which will not prevent intended operationofthe apparatus, but will prevent accidental or inadvertent operationwhich might occur due to the well pressure or pressure of the uid in thewell. 40 It is a still further object of my invention to provideafrelatively simple apparatus which is fool-proof in operation, which issturdy in construction and will therefore -withstand severe shocks andstrainsproduced during the opera-l tion of the apparatus, and one-lwhich is easily cleaned and recharged for reoperation.

A further object of my invention is to provide a method and apparatus inwhich a pressure is first 4built up in the apparatus before the tiring50 charge isA ignited.

It is a further object of my invention to provide an explosive operateddevice, in which an ignition charge is burned in order'to develop heatand pressure within thedevlce, and which .55

' igniting them.

provide an apparatus for perforating a well'hav- 35 of my invention.

4@ s-a of rig.' 2.

' 1 s--e of Fig. e.

- @of my invention.

'on a suitabledrum i5. sheave I4 is a measuring means I6 which in- 65cludes a wheel I1 adapted for engagement' with the cable 'I2, and whichisv connected to a meter is employed to ignite the explosive operatingcharge.

Itis a further object of my invention to provide an explosive operateddevice. whichl inwhich is in communication with the explosive 5 cludes aclosed space or igpitionchamber inwhich heat and pressure are iirstbuilt up andoperating charge chambers which contain ex plosivejcharges,and in which the heat and presl sure or iiameis transmitted through theignition chamber -to the explosive operating charges for -It is a stillfurther object of my inventionto provide an explosive operated device,as pointed 15 out in the preceding pdaragraph, in which the ignitionchamber or.c1osed space is connected to the. different explosive chargechambers by' restraining ports which are of relatively small diameter orarea of cross section.

It is astill further object of my invention to ing the ygenera-lfeatures mentioned above and in which the priming means or ignitingmeans is separated from the -iiring charge of powder, 25 but is incommunicationthere th by a relatively smallopening which pe ts thepriming means or igniting means to ignite the vring charge of powder,but which prevents any ma terial^escape of powder.

Other objects and advantages oi' my invention will be made evident inthe following description of the preferred form of my invention.

Referring to the drawings in-detail:

. Fig. 1 is an e1evationai view showing-the utility U Fig. 2.

Fig. 9 is a sectional view illustrating a'iorm of my invention in whichbut a single projectilel is employed.

Referring to' the drawings in detail. and. parv 55 ticularly' to Fig.'1, thev numeral-.iirepresents the perforating device incorporating thefeatures cylindrical and elongated metal body whichl has jconriected'to-its'upperend 'a exible cable i2 luo ,\vhi'c'h extends upwardlythroughthe well cesing I3 to the surface of the groundwhere it passesovera sheave- I4 and is thereafter wound Associatedwith vthe I8 by meansof a ilexible'cable I9. The purpose of'the measuring means I8 .is toindicate the depth of the'perforating device I I to enable'this Y 70deviceto be lowered into the ground the desired number of; feet, vandwhen it reaches this position to be operated in order thatthe wellcasing I3` will be perforated at'the desired level;

The general'- construction, as well (as the de- -75`ta`ils ofconstruction, are shown in Figs. 2 to It consists essentially oi avinclusive. For the convenience of manufacture.

the perforating device oi myinvention is made in a plurality of parts.However, I do not wish to be limited to the precise details ofconstruetion illustrated. 'Ihe ypreferred form of my invention, asillustrated best in Fig. 2. lincludes a cylindrical and elongated body:25 which is preferably made from. steel or fromisteel alloywhich iscapable of withstanding strains, shocks, and internal pressures. vTheupper end of thev body 25 is provided with-athreaded socket lisa that acollar` or connection member 21 may be secure'd thereto, this connectionmember 2 1 hav` u ing a threaded pin' 28 4which is screwed into .the

-threaded 'socket 26. The connection member 21 'has a threaded pin 29which'is formed at the upper end of an upwardly projecting. shaft 30.Connected to the threaded pin 29 is a cable vsocket 3l, by means ofwhich the cable I2 is connectedto the apparatus. vThe lower end ofthecable i2 extends to the interior of the cable socket 3l and has thestrands thereof separated, after which hot babbitt is poured into theplace. thus providing an enlargement 82 which eRectively secures theseparts together.

. Referring now to the details of construction providedl by thepreferred form of my invention, the body includes a plurality ofshooting means 33 which includes a powder chamber, a cylinder, andprojectile, as will be now de` scribed with reference to Fig. 8.Formedin the body 2E are aplurality of openings 35 which are arranged atdiierent elevations and winch are alternatelyf connected or Joined toopposite sides of the bbdy 26. Each opening 35 has a bottom portionwhich provides a ming-charge chamber or powder chamber 36, and adaptedto be positioned in the firing-charge chamber $6 is a ring charge 3lwhich consists oi' a charge ofVJ powder enclosed in a suitable container3@ which may be made from cloth'or paper. The gter portion oi theopening 3S is provided in t" e vform of a threaded portion 3S which isof larger diameter than the ming-charge chamber 3S, thus providing an.annular shoulder de. Adapted to be screwed into the threaded portion 3@is a barrel or cylinder 4i lua'hich. has an end face Q2 which secures agasket 43 against the shoulder im, thus retaining the ring charge 3llin. place and thus forming a gas-tight seal. lin

order to obtainthe necessary strength to enable a 'building upofinternal pressure and to with ystand external pressure, as well assealing qualit ties, this gasket is preferablymadefrom a sheet of steeland a Vsheet of copper. The barrel or cylinder vSi is provided .with-acylinder bore ad which extends preferably at right' angles to thelongitudinal axisof the body 25 and is in communication with theexterior of the device at its outer end and in communication with the /fgasketl 'at its other end. The outer part or 'the cylinder or barrel HIis provided with Va polygonal'portionl sothat it may be installed orremoved byxthe use of a suitable wrench. T he `cylinder il in` thepreferredfiorm of my invention is a separate part so` as to provide aconvenient means for securingthe gasket Jain placeand to permitlconvenient replacement when vthe 'bores become enlargedlthrough' use.

invention, however is not limited to this particular -arrangementrhndthe term .cylinderl as usedherein and4 `in theclai'ms is to" beconstrued as including cylinders: which' are either separate from orintegral with the body .ma Wise ucynndel b0re" or "borewi'm to beconstrued as covering any opening or sage iri which a projectile issupported or through which the projectile is propelled. Placed' in eachhas suiilcient` mechanical strength to-withstaud well pressures andkeeps the projectile from being forced into the ming-charge chamber. Forrel taining the projectile 48 in place I prefer to use a body of grease48 which illls the outer end of the boreA M, thusholding the projectileI8 against the lgasket 43 and thus preventing the entrance of foreignmatter o r obstructions into 1s the outer part of the bore.

This element of my invention -is operated by igniting or lighting thecharge of powder or firing charge 81, as will bedescribed. This powderupon burning develops a high pressure in the firing-charge chamber Itand ruptures the gasket 43 when the pressure builds up sumclentlw I findthat more force in be applied to the I.projectile by making the ketstrong enough to cause a relatively 'high pressure to be built up.before itl ruptures the gasket and releases.

,This release of pressure applies. a great force and res the projectileI6 outwardly through theV bore I4 with such force thatthe casing I3 willbe easily penetrated andthe projectile will be so forced an appreciabledistance into the surrounding formations.

The ignition means of myinvention includes what I term an ignitionchamber". or space, or unobstructed passage Il which is provided in theform of a cylindrical bore which is drilled into the body 25 preferablyfrom the lower end thereof.'` The lower end oi the ignition chamber. isclosed by a removable plug Il, which plug may be removed after operationofthe perforating device for` the purpose of cleaning the ignitionchamber $0. This plug 5l. is, of course,-

provided with a suitable gasket l2 to forma gas-tight seal. `Theignition-chamber or space,

or passage 5l is closed from communication with the exterior of the body25; Connected to each a of the nring-Lcharge chambers 36 is an ignitionport 88, which ignition ports are also connected. to the ignitionchamber B0 which extends in a vertical direction adjacent the differentringw charge 'chambers 3l. The ends of the ignition ports 5t adjacentthe firing-charge chambers $6 are reduced in sise as shown at N for thepurpose of diminishing the reduction of pressure by escape of gasthrough the ignition ports Bt u after the rin'g charges Il have beenlighted.

- The ignition means of my invention also lncludes a flame producingmeans lwhich is pro- -vided by an ignition-charge chamber VUt which isprovided by an opening B1 formed laterally into 50 the body 25 from oneside thereof as illustrated in Figs. 2 and 1. The ignition-chargechamber56 is in communication with the upper end of the ignition chamber Il andis adapted to containan ignition charge Il which is enclosed in asuitable container Si which may be clothor paper. This'ignition charge5l, as will be seen from Figs. 2 and 'l'. projects slightly into theignition chamber 5l. The outer end of the opening 51 is provided in theform of an enlarged threaded portion i6 which threadedly receives aclosure plug 8l which, when screwed in place -by the application of thewrench 82, secures a gasket I3. against a shoulder I4 of the opening il,thusforming a gas-tight seal.

Upon the lighting-oi the ignition charge se.

aiis'vsgsso'P pas! vits win be descriiied presently. the .burning of thepowder produces a flame and considerable heat, and this flame isforcedinto the upper end of the ignition chamber' 5I andalmost-instantaneously rliasses downwardly through the entire lengthofthe ignition chamber. The flame or the intense heatof -the llame, whichis suiilcient l to cause an igniting of the ring charges 81, passesyfrom the ignition chamber 50 through the ignition ports 53 and intocontact with the dringcharges 31, ,thus igniting or lighting'them andcausing an operation as pointed out heretofore.

Thev action ofthe ignition means of my invention is such as to produceasubstantially simultaneous firing or lighting ofall of the firingcharges 31 so that all of the projectiles 48 are shot from theperforating device at substantially the same time. This is one of theimportant features of my invention, since it produces a very heavyexplosion, and the projectiles substantially simultaneously striking thecasing and entering the surrounding formation set up very heavyvibrations which are conducive to the providing of oil channels wherebyoil may more free- -ly ilow to the casing for passage through theperforations of the casing into the well.

A further important feature is thalthev ignition'chargeltwhen ignitedinitially builds up a pressure in the apparatus so that when the firingcharges are ignitedhthere willv not be a lossl of power or pressure such as would be in' volved if. it were necessary to employ the pressureof the .ring charges to buildup the pressure in the apparatus.

` It willbe 'seen from the foregoing discussion that the ignitionchamber Bland the ignition ports B3 provide a. 7means for conveying thellame produced bythe burning ofJthe ignition charge i 58 to or intocontact with the .various iiring` charges s1. It will further be seenthat the ignition charge 58 constitutesa means for producing a llame ormeans for producing an igniting heat.

- My invention alsol includes a means for lighting the ignition chargeand this pant ol' my in vention includes a chamber 0B which ispreferably formed in the body 28 from the upper end thereof and which isreduced in sise at its lower end so .itsA

as to provide an annular shoulder Gl. Adapted to be placed y in thechamber .85 against the shoulder 68 is a pu'imllis` device which, forconvenience, is. in the form .of a blankv cartridge 81 which includes apercussion cap anda' small priming charge which is ignited thereby. Itwill be seen that the lower endof the chamber .8B is in communication.with the ignition chamber.

-so .that when Vthe priming charge burns it will in turn light theignititm charge 58. The cartridge l1 may be installed' or removed. fromplace through a breechope'ning B8 which communicates with the chamberOldlrectly above the shoulder 68 and which, is ordinarily closed by aplug $8 which secures a suitable gas-tight gasket 10 in place as shown.By removing the plug C! and also .the plug 6|, which may be done afterthe device has been operateda suitable device may be inserted upwardlythrough the lower end ofthe chamber 8l for forcing the cartridge 81 upward, and the cartridge 61 may then be removed.

through the breech opening 68.

, As a part of the means for lighting the ignition charge my inventionprovides a percussion means. This percussion means includes a percussionrod 'Il which extends downwardly into the chamber tip 'i8 formed on thelower end thereof. 'l'.he

A6B above the cartridge 61 and has a percussionportion of the connectingmeans 21. The upper end of the percussion rod' 15 has a small horizontalopening 80 for receiving a retaining means or shear pin 5|, theextending ends o f the shear pin resting on .the lower wall 82 whichdefines the bottom of the slot 19. Thepurpose of the retaining means 8|is to support the percussion rod 15 in the position shown in Fig. 2 andto hold it in that position so that any pressure within the Weil or thepressure of theuidwithin the well -willnot, when applied to the upperend of the percussion rod 16, force it downwardly, as might occur werethis precaution not taken. This would either result in an accidentalfiring of the perforating device or a destruction of the percussion capso that it would not operate at the desired time. The percussion rod 15,being located wholly within the perforating device. may be referred toas an internal part of the percussion means.

Surrounding theshaft 80 and the socket 3| is a percussion sleeve 8Ewhich, being located on the outside ofthe device, may be referred to asan external part. The upper end. of the percussion sleeve 8i? has anopening 08 through which the cable |2 extends, and the remaining partthereof has a relatively large cavity 81 within which the shaft andsocket. parts 3d and 3|, rest. For the purpose of preventing unduevibration or movement of the percussion sleeve 05 during the lowering ofthe device l.' provide a 4friction means which, vas shown best in Fig.4, is in the form of diametraliy opposed screws 88 carried by threadedl'openings 80 of the percussion sleeve B5 which have inner ends 0|whichv extend into vertically elongated slots 93 formed on the exteriorof the shaft 80. By. suitable adjustment oi. these screws la the desiredfriction may be obtained which will prevent rattling or movement, butwhich will not prevent proper operation of the percussion means.

The percussion means of my invention also includes a yoke ordisconnectable means v93 which, as'fshown in Figs. 2 and 5, extendshorizontally through the slot 19 and engagesv the upper end of thepercussion rod 15. The ends, 94 ofthe yoke 08 project outwardly from theshaft 30 and are engaged by-the lower end 85 of the percussion sleeve85. Shoulders 06 are provided for p'reventing lateral movement andinadvertent re-g moval oi' the yoke l52%. This yoke 93 is removable bywithdrawing the screws 59 and raising the percussion sleeve 85. Whenthisis done the yoke I3 may be removed from place and the percussion sleeve85 may be lowered so that the lower end thereof engages the upper end 55of the large anything to .get into the'slot and inadvertently force thepercussion rod downwardly. Ordi? 'narily I prefer to remove the yoke andlower the percussion sleeve whenever the apparatus is-being transportedand, to properly position these parts, as shown in Fig.. 2, Just beforetheperiov 2,154,859 rating device 'is ready to be lowered into the well.

vFor the purpose of delivering va blow to the percussion means I providea hammer Ill which, as shown best in Fig. 3, is preferably made in twoparts l0| and |02 hinged at |03 and secured in closed positiony by meansof a screw Ill. This hammer |00 has an opening |05 through which" the.cable I2 extends'when the hammer isy positioned on the cable as shownin Figs. 1 and 2.

The hammer is made of this-type so that it need not be placed on .thecable until the perforating device has reached theI desired position andthe xov operator is ready to fire the charges.- He then places thehammer around the cable, secures it in place by proper manipulation ofthe screw |04, and then drops it into the well. e hammer follows thecabledownwardly and strikes the upper end of the percussion sleeve 55.The force is transmitted through the lpercussion sleeve and the yoke andto the percussion rod 15. 'I'he force is suiilcient to shear theretaining means or shear pin 0|, thus permitting-the percussion rod tobe iorceddownwardly with a suilicient blow to ilre the percussion capand ignite the priming charge of the cartridge 51.

It is believed that from the foregoing the details of construction andthe operation of my ln- .been properly placed in the apparatus and theonly thing ynecessary'for rendering the devicel operable is to raise thepercussion sleeve 55, insert the yoke 83, and install the frictionscrews 09. This device -is then lowered into theY well by means of thecable |2,fand when'the device has reached the depth at which theperforating operation is to be performed, this being indicated by themeasuring means is, the cable l2 is locked in a stationary position. andthe operator then places the hammer itl@ on the cable i2. 'I'he hammer|00 isl then released and its falls downwardly along the cable i2 andstrikes the upper end of the percussion sleeve 85. This produces thesequence of operation described heretofore and consists of operating thepercussion means which ilres the priming charge.

This in turn lights the ignition charge 58 which produces the vflamewhich ows downwardly through the ame conveying space which includes theignition. chamber and the ignition ports 53 building up an internalpressure as previously explained. -This fiame; passing into igniting orlighting contact with the ring charges I1, ignitesA the firing charges31 and produces a gas pressure which when it builds up sufficientlyruptures the gaskets .42 and shoots the projectiles I5 outwardly throughthe ports M, thus piercing the well casing Il and forming passages inthe surrounding formation.

After the device ihas been' thus discharged `it is raised to f thesurface of the ground, after which the-device is cleanedreloaded, andset for a subsequent operation. The cleaning is done by removing the.plug 5I so that the ignition chamber 50 may be cleaned; by removing theplug 5| so-that the ignition-charge chamber 55 may be' i been ruptured,and new projectiles 56 and bodies of grease 48 are installed in thebarrels or cylinders 4|. In addition to this a new shear pin 8l isinstalled in the opening 8u. .This places the device in condition forreuse and it is now ready to again be lowered into this well or someother well for further operation.

In the form of my invention shown in Fig. 9v I employ but a singlefiring-charge chamber and projectile. This type of device is used forspecial jobs, such for example as where it is necessary to perforatemany strings of casing and layers of cement, in which case it isnecessary to have a very heavy body and a very large charge of powder sothat suiiicient penetrating force can be obtained. In this alternativeform of my invention all of the parts are the same except as will benoted, and therefore the same numerals will be applied to this form ofmy invention as have been applied to corresponding parts ofthe formof myinvention illustrated in Figs. 1 to 8 inclusive. In the form of myinvention now being described the percussion cap and priming means 61instead of being in communication with an ignition charge, as in theiirst form of my invention, of itself acts as the igniting means orignition charge. 'I'he device includes but a single powder chamber 38and companion parts, as illustrated in Fig. 8, and is in communicationwith the priming means 61 by means of arelavtively small communicatingport lill which, in

this form of my invention, constitutes the means for conveying the ameor igniting heat to the tiring charge 31.

' In view of the fact that the eilitciency of the apparatus depends uponbuilding up an extremely high pressure in *the powder -chamber 38, Ihave separated the priming means 61 from the powder chamber 38. Thecommunicating port H is so small that the loss of pressure through thissmall opening isy negligible. It is, however, suiciently large to permitthe priming means 61 to ignite the tiring charge 31 whenever thepercussion device is operating.

Although Ihave described herein the preferre form of my invention, itshould be understood that various changes .and modications may be madewithoutdeparting from the spirit and scope of my invention as definedin, the appended claims. l A

I claim asmy' invention:

1. In a device for perforating well casings in a well, the combinationof walls forming an ignition-charge chamber; an ignition'charge in 'saidchamber:

walls forming a 1 firing-charge chamber; aring charge in saidfiring-charge chamber; a cylinder having a cylinder bore and positionedfor communication with said ringcharge chamber;v a projectile in saidcylinder bore; lighting means for lighting said ignition charge forproducing a ame; and walls, forming an unobstructed. name-conveyingspace, closed from communication `with the exterior of said device, forconveying the name to said ringchargechamber for ring said 'ilringcharge.

2, In a device for perforating well casings in a well, the combinationof: walls forming an said .firing charge chambers for iring said iiringcharge.

3. In a device for perforating well casing in a. well, the' combinationof: walls forming an ignition-charge chamber adapted Yto receive anignition charge; walls forming 'a'plurality ofringcharge chambers; aplurality of cylinders each having a cylinder bore and each positionedfor communication with one of said tiring-charge chambers; a projectilein each of said cylinder bores; lighting means for lighting the ignitioncharge for producing a flame; and walls' forming an unobstructedname-conveying space, closed from communication with the exterior ofsaid device, for conveying the flame to said firingcharge chambers forring same.

4. In a device for perforating well casing in a of. said firing-chargechamberspa projectile in each of said cylinder bores; lighting .meansfor lighting the ignition charge for producing a iiame; walls forming anunobstructed chamber into which the iiame passe's'whichis formed by theburning of the ignition charge; and walls vforming restraining portsconnected to said unobstructed chamber and each chambers.

5. In .a device for perforating well'casing in a well, the combinationof a plurality oi' cylinders having cylinder bores; a projectile in eachof of said ming-charge said cylinder' bores; a firing charge adjacenteach A of said cylinders: an ignition charge; priming means-for primingsaid ignition charge; percussion means for operating saidpriming means,

saidpercussion means -having an internal part,

an external part, and disconnectable means normally operably connectingsaid parts together: a hammer for operating said percussion means; andmeans in the form of an unobstructed pas? sage closed from communicationwith the exterior or, said device and in communication with saidignition charge and said firing charges.

6. Ir azdevice for perforating well casing in` a well, the combinationof: a plurality of cylinders having cylinder bores; a projectile in eachof said `cylinder bores; a ilring charge adjacent each of saidcylinders? an ignition charge; priming means `for priming said ignitionchargeypercussion means for operating said priming means, saidpercussion means `having .an internal part, external part,disconnectable means normally operably connecting saidl parts together,and retaining means 'associated with said internal part,

forpreventing inadvertent actuation; a'hammer for operating saidp'ercussionmeans;` and means.

in the form of an' unobstructed passage :closed from communication withthe exterior of said device and in communication `saici ignition chargeand said tiring charges.

' 7. Ina device for perforating well casing in a well, thecombinationof: a plurality oi.' cylinders having cylinder bores; aprojectile in each of said cylinder bores; a firing charge adjacent eachof said cylinders; an ignition charge; priming means'ior priming saidignition charge; percussionmeans .I or operating' said priming means..said percussion means having an internal part, an external part, anddisconnectable means normally `operably connecting said parts together;a hammer adapted to be dropped into engagement with said external partfor operating said percussion means; and means in the form of anunobstructed passage closed from communication with the Yexterior ofsaid device and in communication with said ignition charge amd saidring' charges.

8. In a device -for periorating well casing in a well, the combinationof: a cylinder having la vcylinder bore; a projectile in said'cyllnderbore;

afilring charge adjacent said cylinder; anignition charge remote fromsaid firing charge; means for igniting said ignltioncharge; and means iny the form of 1an unobstructed passage closed from communication with'the exterior o! said device and in communication with s aid ignitioncharge and said firing charge. s

9. In a device tot perioratingl wellcasing Vin awell'. the combinationoi: walls forming an ignition 'charge chamber, adapted 4to receive anignition charge; walls forming a tiring-charge chamber: a cylinderhaving a cylinder bore positloned for communicationl with saidtiring-charge` chamber; 'a projectile in said cylinder bore;

lighting means for i'gnlting said ignition chargeY fior producing ahamm-walls forming an ignition chamber into which the flame passes whichis formed by the burning oi saidrignition charge:

and walls forming a port connected to said igni-v tion chamber and saidfiring-charge chamber.

' municating and pressure restraining borezcon@v 10.y In a device for`pex'iorating well casingin 'a'v we1lthe .combination of: walls vforminga tiring-charge chamber adapted to receive a firing charge: a barrelhaving a cylinder bore posi- -tioned for communication with saidtiring-,charge chamber; aprojectile in said cylinder bore; walls forminga priming means chamber closed from communication with the .exterioroisaid device;

a priming means in s'aid priming means chamber; means whereby'saidpriming Ameans is i'gnited; and-walls -iorming a relatively smallcomnected to sald priming means and .said ringcharge chamber. f

- 11. 4In aff device for periorating well casing in a well, thecombination 01:' a cylinder havinga cylinder bore; a projectile in`saidfcylinder bore:

a iiring charge adjacent said cylinder; an ignition 12. In a device forperforating well casing ina V "weli, Vther-combination oi: walls formingan ignition-charge chamber, adapted to receive an. ignition chargeywallsforming a firing-charge- 7s chamber; a cylinder having a cylinder boreposiarmste tioned for communication with said ming-charge l A chamber: aprojectile in said cylinder bore;

lighting means for igniting said ignition charge structed space incommunication `with said iiring charge'and said ignition charge andsubstantially closed from communication with the exterior oi said deviceso that when said ignition charge is burned heat` andpressureare'thereby developed in said space; and walls forming a restrainingportconnected to saidv ignition-charge chamber and to said tiring-chargechamber whereby said heat vand pressure are transmitted -to said ilrinscharge for iiring the same and propelling said projectile.

i3. In'a device for perforating well casing in a well, the combinationof: walls forming an ignition-charge chamber adapted to receive anignition charge; -walls forming a plurality of iiring-charge chambersspaced from said ignition charge and each adapted to receive a i'lringcharge; a plurality of cylinders each'having a cylinder bore and eachpositioned for communication with one of said firing-charge chambers;a--projectile' in each of said cylinder bores; lighting means forlighting said ignition charge for burning same; walls `i'orxning a spacesubstantially closed lfrom the exterior oilsa'id device, and in-communication with said ignition-charge chamber, so that when saidignitionl charge is burned heat and pressure 'are thereby developed insaid for producing a flame; wallsforming an unobspace; and walls formingaplurality of ports,

each port being connectedv with one of said tiringcharge chambers .andsaid space and byr means o i which said heat reaches said ilring chargesand ignites them;

A 14.-.In a device for periorating vwell casing iny awell,` thecombination oi: walls-forming a plurality o! firing-charge chambers eachadapted to receive'a nring charge; -a plurality of cylinders each havinga cylinder bore and each positioned for communication with one of saidtiring-'charge chambers; aprojectile in each'of said cylinder .-bores;walls forming a-space closed from the' exterior oisaid device;` anignition charge in communication with said space and adapted to beburned to produce heat and pressure in said *space; and walls forming aplurality o! ports.A each port being connected with one oi' saidfiring-- charge, chambers and said space and by means of which said heatreaches said nring charges and.

ignites them. 15. In a device for perforatlng well casing inl a well,the combination of: walls forming a plurality of flring-chargechamberseach adapted to' re-' ceive a iiring charge; a plurality of cylinders lfor communication with one of said tiring-charge chambers;a projectile4in each Iof said cylinder bores; wallsforming a space closed from theexeach having a cylinder bore and each positioned terior of said device;an ignition charge in communication with said space and adapted to be'burned to produce heat and pressure in said space; and walls forming aplurality of relatively small restraining ports, each restraining portbeing connected with one of saidnring-charge chambersv andy'said space,and constituting a means whereby said heat and pressure are nrst builtup in said space and thereupon said heat passes through said restrainingports and ignites said firing charges;l

16..Ir'1 a perforating gunoi the character described, the combinationof: a body providing a chamber to receive a priming means; percussionmeans for said priming means' comprising a movl, i 2,154,859 I ableinner part, a movable outer part 4.and a re-7 movableinterconnectingpart adapted when in place to connect said inner andouterparts; a shear pin engaging said inner part to hold the same ininoperative relation. to said priming means; and operating means forimparting a force to saidgouter part, for transmission througn saidinterconnecting part tosaid inner part, to cause shearing of said shearpin and actuation of said priming means.

17. In a perforating gun of they character de` scribed, the combinationof: a body having a chamber to receive a priming means in operativeposition; a percussion member supported so that it may be moved so as toactuate said priming means; a guard supported on said body .so as toprotect the outer end of said percussion member from inadvertent impactby .an external object; and an insertable member adapted to be placed inposition to form a connection between said guard and said percussionmember whereby iorce to move said percussion member may be transmittedthereto through the medium of said guard and said insertable member.

18. In a well periorating gun of the class described, the combinationof: a body providing a cylinder bore havinga projectile, a ilring chargechamber adjacent said cylinder bore having a iiring charge for.propelling said projectile, an ignition charge chamber spaced from saidring charge chamber having an ignition charge, and an ignition chamberclosed from communication with the exterior of said body and in communi--cation with said ignition charge chamber and said iiring chargechamber; and means for igniting said ignition charge.

19. In a well perforating gun of the class described, the combination ofa body providing a cylinder bore having a projectile, a ring charge.

chamber adjacent said cylinder bore having a iiring charge forpropelling said projectile, an ignition charge chamber spaced from saidBring charge chamber having an ignition charge, an ignition chamberclosed from communication with the exterior of said body fand incommunication with saidignition charge chamber, and

a restraining port in communication with said f ignition chamber andsaid firing'r charge chamber; and means for igniting said ignitioncharge.

20. In a well performing gun of the class described, the combination of:a body providing a plurality oi cylinder bores each having a projectile,a plurality o! iiring charge chambers each positioned adjacent one ofsaid cylinder bores and each having a firing charge, an ignition Vchargechamber spaced from said firing charge chambers having an ignitioncharge, and an ignition chamber closed from communication with theexterior of said body and in communication with said ignition chargechambers and said ring charge chambers; and means for igniting saidignition charge.

21. In a well perforatinggun of the class described, the combination of:a body providing a plurality of cylinder bores each-having a projectile,a plurality of ring charge chambers each positioned adjacent one of saidcylinderbores and each having a firing charge, an ignition chargechamber spaced from said firing charge cham` bers having an ignitionkcharge, an ignition charnber closedfrom communication with the exterioro! saidbody and in communication with said -ignition charge chambers,and a plurality of re-.

strainingiports e'ach being in communication with said ignition chamberand one of said -riug ythe combination of: a body providing an explosivecharge chamber for receiving said explosive charge therein, an ignitioncharge chamber spaced from said explosive charge for receiving anignition charge therein, and an ignition chamber closed fromcommunication with the exterior oi said body and incommunication withsaid ignition charge lchamber and said explosive chargeI chamber, andmeans forigniting said ignition charge to cause said explosive charge toperform an operation in s d well.

23. In a device adapted to llowered into a well and operated therein byan explosive charge, the combination of: a body providing an explosivecharge chamber for receiving `saidv explosive charge therein, anignition charge chamber spaced from said explosive charge for receivingan ignition charge therein, an ignition chamber closed fromcommunication with the exterior of said body and in communication withsaid ignition charge chamber and said explosive chargechamber, and-arestraining port in communication with said ignition chamber and saidexplosive charge chamber, and means for igniting said ignition charge tocause said explosive charge to perform an operation in said well.

24. In a device for perforating well casing in a well, the combinationof t a body adapted to be lowered into the well, said body having aboreadapted to receive a projectile, and a powder chamber adapted to receivea charge of powder a well, the combination of: a bodyV adapted to belowered into the well, said body having a bore adapted to receive aprojectile, and a-powder chamber adapted to receive a charge of powderwhich when iired will propel said'projectile from said bore; andpercussion means for firing said charge of powder, including4 an innerpercussion member supported within said body, an outer percussion membersupported on the exterior of said body and adapted to be struck by ahammer means, and a removable member operably connecting said percussionmembers together, said percussion means being -rendered inoperative whensaid removable member is removed.

26. In awell perforating device of the character described, thecombination of: a body having a chamber adapted to receive a charge ofpowder, there being an opening extending upwardly from said chamber, thelower end of said opening being adaptedto receive' a priming means, aridthere being a port communicating with said opening at a point adjacentthe ,position of said priming means therein and through which saidpriming' means may be inserted or removed; means in said opening for`setting off said priming means; and a removable closure member for saidport.

27. The method of iiring a projectile from aV gunV perforator for a wellcasing. which includes .the steps of confining an explosive charge inA achamber adjacent saidprojectile; coniining another explosive charge inanother chamber spaced from said first mentioned chamber; igniting saidother explosive charge to produce heated gases and build up pressure insaid other chamber; and forcing said heated' gases by said pressurethrough a restricted eway between said chambers to ignite said firstmentioned explosive charge and fire said projectile.

28. The method ci simultaneously nring a plurality ot projectiles from agun pertorator for a well casing, whichincludes the steps of: confiningan explosive charge in each of a plurality o! chambers; each o! which isadiacent'at least one of 'said projectiles; confining another explosivelawww u 1 charge in another chamber spaced from cacho! said firstmentioned'chambers: igniting said other explosive charge to produceheated gases and buildup pressure in said other chamber; and forcingsaid heated gases by said pressure through restricted passagewaysbetween said other charnberfand each of said plurahty of chambers to vsimultaneously ignite said iirst mentioned charge

